Methods and systems for automating deployment of applications in a database environment

ABSTRACT

In accordance with embodiments disclosed herein, there are provided mechanisms and methods for automating deployment of applications in a multi-tenant database environment. For example, in one embodiment, mechanisms include managing a plurality of machines operating as a machine farm within a datacenter by executing an agent provisioning script at a control hub, instructing the plurality of machines to download and instantiate a lightweight agent; pushing a plurality of URL (Uniform Resource Locator) references from the control hub to the instantiated lightweight agent on each of the plurality of machines specifying one or more applications to be provisioned and one or more dependencies for each of the applications; and loading, via the lightweight agent at each of the plurality of machines, the one or more applications and the one or more dependencies for each of the one or more applications into memory of each respective machine.

CLAIM OF PRIORITY

This application is related to, and claims priority to, the provisionalutility application entitled “METHODS AND SYSTEMS FOR AUTOMATINGDEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,”filed on May 18, 2010, having an application number of 61/345,977, theentire contents of which are incorporated herein by reference.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

TECHNICAL FIELD

Embodiments of the invention relate generally to the field of computing,and more particularly, to methods and systems for automating deploymentof applications in a multi-tenant database environment.

BACKGROUND

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also correspond todisclosed embodiments.

Conventional large scale farms of machines or machine farms lacksufficient automated architecture that provides functionality toautomate provisioning for use of each or any of the respective machinesin the farm, including remote installation and upgrading of testapplications, Java™ based applications, and the like, as well as generalmanagement and maintenance of machines within the farm. Further lackingin conventional mechanisms is functionality to easily run the respectiveapplications hosted by such machines in an automated fashion, withoutrequiring human intervention.

Improved mechanisms for automating deployment of applications tomultiple machines, such as those operating within a machine farm or adatacenter, is therefore desirable. Solutions to the above mentionedproblems and other benefits of Applicants' disclosed embodiments aredescribed in additional detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are illustrated by way of example,and not by way of limitation, and can be more fully understood withreference to the following detailed description when considered inconnection with the figures in which:

FIG. 1 depicts an exemplary architectural overview of the environment inwhich embodiments may operate;

FIG. 2 depicts an alternative exemplary architectural overview of theenvironment in which embodiments may operate;

FIG. 3 shows a diagrammatic representation of a system 300 in whichembodiments may operate, be installed, integrated, or configured;

FIGS. 4A, 4B, and 4C are flow diagrams illustrating methods forautomating deployment of applications in accordance with disclosedembodiments; and

FIG. 5 illustrates a diagrammatic representation of a machine in theexemplary form of a computer system, in accordance with one embodiment.

DETAILED DESCRIPTION

Described herein are systems, devices, and methods for automatingdeployment of applications in a multi-tenant database environment, forexample, automating application deployment onto respective machineswithin a machine farm without requiring human intervention.

In a particular embodiment, such mechanisms include managing a pluralityof machines operating as a machine farm within a datacenter by executingan agent provisioning script at a control hub within the datacenterinstructing the plurality of machines to download and instantiate alightweight agent; pushing a plurality of URL (Uniform Resource Locator)references from the control hub to the instantiated lightweight agent oneach of the plurality of machines specifying one or more applications tobe provisioned and one or more dependencies for each of the one or moreapplications; and loading, via the lightweight agent at each of theplurality of machines, the one or more applications and the one or moredependencies for each of the one or more applications into memory ofeach respective machine.

In the following description, numerous specific details are set forthsuch as examples of specific systems, languages, components, etc., inorder to provide a thorough understanding of the various embodiments. Itwill be apparent, however, to one skilled in the art that these specificdetails need not be employed to practice the embodiments disclosedherein. In other instances, well known materials or methods have notbeen described in detail in order to avoid unnecessarily obscuring thedisclosed embodiments.

In addition to various hardware components depicted in the figures anddescribed herein, embodiments further include various operations whichare described below. The operations described in accordance with suchembodiments may be performed by hardware components or may be embodiedin machine-executable instructions, which may be used to cause ageneral-purpose or special-purpose processor programmed with theinstructions to perform the operations. Alternatively, the operationsmay be performed by a combination of hardware and software.

Embodiments also relate to an apparatus for performing the operationsdisclosed herein. This apparatus may be specially constructed for therequired purposes, or it may be a general purpose computer selectivelyactivated or reconfigured by a computer program stored in the computer.Such a computer program may be stored in a computer readable storagemedium, such as, but not limited to, any type of disk including floppydisks, optical disks, CD-ROMs, and magnetic-optical disks, read-onlymemories (ROMs), random access memories (RAMs), EPROMs, EEPROMs,magnetic or optical cards, or any type of media suitable for storingelectronic instructions, each coupled to a computer system bus.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct more specializedapparatus to perform the required method steps. The required structurefor a variety of these systems will appear as set forth in thedescription below. In addition, embodiments of are not described withreference to any particular programming language. It will be appreciatedthat a variety of programming languages may be used to implement theteachings of the embodiments as described herein.

Embodiments may be provided as a computer program product, or software,that may include a machine-readable medium having stored thereoninstructions, which may be used to program a computer system (or otherelectronic devices) to perform a process according to the disclosedembodiments. A machine-readable medium includes any mechanism forstoring or transmitting information in a form readable by a machine(e.g., a computer). For example, a machine-readable (e.g.,computer-readable) medium includes a machine (e.g., a computer) readablestorage medium (e.g., read only memory (“ROM”), random access memory(“RAM”), magnetic disk storage media, optical storage media, flashmemory devices, etc.), a machine (e.g., computer) readable transmissionmedium (electrical, optical, acoustical), etc.

Any of the disclosed embodiments may be used alone or together with oneanother in any combination. Although various embodiments may have beenpartially motivated by deficiencies with conventional techniques andapproaches, some of which are described or alluded within thespecification, the embodiments need not necessarily address or solve anyof these deficiencies, but rather, may address only some of thedeficiencies, address none of the deficiencies, or be directed towarddifferent deficiencies and problems where are not directly discussed.

FIG. 1 depicts an exemplary architectural overview 100 of theenvironment in which embodiments may operate. Within datacenter 110,also referred to as a host organization, are a plurality of machines105A-G operating as a machine farm 115. A network 125 connects themachines 105A-G with a control hub 195 and an application repository190.

In one embodiment, control hub 195 executes an agent provisioning script(e.g., via agent provisioner 120). Agent provisioner 120 or an agentprovisioning scrip instructs each of the plurality of machines 105A-G todownload and instantiate a lightweight agent 130. The lightweight agent130 is depicted as a deployable 145 within the application repository190. In alternative embodiments, the lightweight agent 130 resideswithin the control hub 195 and is pushed to the respective machines105A-G directly from the control hub 195.

Lightweight agent is depicted as having already been downloaded to someof the machines 105A-G, including machine 105A, machine 105B, machine105C, and machine 105D. Machines 105E, 105F, and 105G do not yet have alightweight agent downloaded or instantiated upon them.

Agent provisioner 120 or an agent provisioning scrip additionally pushesa plurality of URL (Uniform Resource Locator) references 170 from thecontrol hub 195 to the instantiated lightweight agent 130 on each of theplurality of machines (e.g., machines 105A-D having the lightweightagent 130 downloaded thereupon). The URLs 170 specify one or moreapplications 135 to be provisioned and one or more dependencies 140 foreach of the one or more applications 135.

The lightweight agent 130 at each of the plurality of machines loads theone or more applications 135 and the one or more dependencies 140 foreach of the one or more applications into memory of each respectivemachine (e.g., machines 105A to 105D as shown in FIG. 1). Loading theone or more applications 135 and the one or more dependencies 140 mayconstitute the control hub 195 triggering or initiating the loading ofthe one or more applications 135 and the one or more dependencies 140,for example, by sending instructions, or manipulating the lightweightagent 130 via commands issued (e.g., through a command shell or otherinterface) at each of the machines, responsive to which the machinesdownload the necessary applications 135 and dependencies 140 based onthe URLs 170. In an alternative embodiment, once deployed, eachlightweight agent 130 operates autonomously to retrieve the necessaryapplications 135 and dependencies 140 based on the URLs 170 upon receiptof the URLs or responsive to receiving the URLs 170.

Within application repository 190, two interfaces are depicted, controlinterface 160 and URL interface 165. Control interface 160 provides amechanism over which control hub 195 may interact with applicationrepository 190 as necessary. URL interface 165 provides a mechanism overwhich the machines 105A-G in the machine farm 115 may interact with theapplication repository. More particularly, the machines 105A-G, uponhaving received URLs 170 from the control hub 195, may commence todownload the one or more applications 135 to be provisioned and one ormore dependencies 140 for each of the one or more applications 135 fromthe application repository 190, as specified by the control hub. Forexample, the machines 105A-G may communicate with the applicationrepository 190 via HTTP (Hyper Text Transfer Protocol) and/or FTP (FileTransfer Protocol), or other available protocols, as specified by theone or more URLs 170.

In one embodiment, the lightweight agent 130 is a small program whichfunctions similar to a bootstrap loader insomuch as it provides eachrespective machine 150A-G having the lightweight agent 130 with minimalbut sufficient logic to retrieve and load more sophisticatedfunctionality. For example, in development and testing of one embodimentas described herein, the deployable 145 lightweight agent 130constituted less than 300 total lines of code and required nothing morethan a base JDK (Java Development Kit), hence the “lightweight”description. Obviously, a deployable agent to serve such a role may varyin size and sophistication, but still operating in accordance with thedisclosed embodiments.

In one embodiment, the control hub 195 manages a database 155 specifyingrelationships between all available applications 135 and alldependencies 140 for the available applications 135. For example, whilemultiple dependencies 140 are provided (e.g., classes, objects, linkableprograms, etc.), not all dependencies 140 are required for everyapplication 135. Additionally, while several different and distinctapplications 135 are available, different subsets of dependencies 130will be required depending on which application 135 is being loaded andutilized. These relationships and requirements are tracked by database155 in accordance with one embodiment.

The applications themselves may be test cases or test suites forvalidating code, testing interfaces, and the like. Some applications mayconstitute grid based functionality in which each machine 105A-Goperates as a node within a grid that, for example, computes data andreports back results for use in a master application.

FIG. 2 depicts an alternative exemplary architectural overview 200 ofthe environment in which embodiments may operate. The lines connectingvarious components explicitly to the network 125 have been removed forthe sake of clarity, however, the components are obviously stillcommunicatively interconnected via the network 125. Additionally, whileonly internal detail of machine 205B is shown, the other machines 205Aand 205C operate in an identical fashion. In some embodiments, thenumbers and scale of deployed machines may be significant, for example,well into the hundreds of machines controllable via a single controlhub. FIG. 2 depicts in additional detail the manner in which machines(e.g., 105A-D) of FIG. 1 and machines 205A-C here, may be provisioned inaccordance with disclosed embodiments.

For example, in accordance with one embodiment, the agent provisioner120 or agent provisioning script instructs each of the plurality ofmachines (e.g., 205A, 205B, and 205C) to download and instantiate thelightweight agent 130. In such an embodiment, instructing the pluralityof machines (e.g., 205A, 205B, and 205C) to download and instantiate thelightweight agent 130 includes the agent provisioner 120 or agentprovisioning script to: access a list 295 specifying a location name foreach of the plurality of machines 205A-C to be provisioned with thelightweight agent. The list 295 may reside locally within control hub195 or, in alternative embodiments, may reside within and be accessedfrom database 155. List 295 may include a listing of one or more dataincluding: host names, host IP addresses (Internet Protocol addresses),MAC addresses (Media Access Control addresses), passwords, encryptionkeys, zoning, hardware type or hardware specification data, etc.Database 155 further includes a table structure 290 specifying therelationships between all available applications 135 and alldependencies 140 for the available applications 135, which may beutilized by the control hub 195 in determining what applications anddependencies to provision to the machines 205A-C (e.g., by pushing URLs170 corresponding to the determined applications 135 and alldependencies 140). The doubled headed line between agent provisioner 120and database 155 depicts the interactions by which the agent provisionerretrieves information from database table structure 290 or list 295, asnecessary.

In such an embodiment, instructing the plurality of machines 205A-C todownload and instantiate the lightweight agent 130 additionallyincludes, for each of the plurality of machines 205A-C specified by thelist 295: a) logging in to a command shell 285 (e.g., a Command LineInterface (CLI) or other remotely accessible interface) on the specifiedmachine (e.g., one of 205A, 205B, and 205C) from the control hub 195; b)instructing, by issuing commands to the command shell 285, the specifiedmachine (e.g., one of 205A, 205B, and 205C) to download the lightweightagent 130 from the control hub 195; and c) instructing, by issuing thecommands to the command shell, the specified machine (e.g., one of 205A,205B, and 205C) to start the lightweight agent 130. In alternativeembodiments, the control hub 195 may access the command shell 285 andinstruct each respective machine to download the lightweight agent 130from the application repository 190. The straight double headed linebetween agent provisioner 120 and the command shell 285 of machine 205Brepresents the interaction and connectivity between the two elements infulfillment of the above communication of commands and triggering of thedescribed events.

In one embodiment, each of the plurality of machines 205A-C pulls thelightweight agent 130 from the control hub 195 responsive to the agentprovisioning script or the agent provisioner 120. In such an embodiment,each of the plurality of machines 205A-C pulls the one or moreapplications 135 and the one or more dependencies 140 for each of theone or more applications 135 from a central application repository 190.Therefore, in accordance with the described embodiments, control hub 195may cause the machines 205A-C to pull the lightweight agent 130, or thecontrol hub 195 may directly push the lightweight agent 130 to each ofthe machines 205A-C (e.g., via remote copy or other such mechanismscapable of pushing data and/or files onto another machine).

In accordance with one embodiment, the control hub 195 and the centralapplication repository 190 each reside on physically separate anddistinct computer servers. In accordance with one embodiment, each ofthe plurality of machines 205A-C in the machine farm 115 are physicallyseparate and distinct computer servers from the control hub 195 and fromthe central application repository 190. In such an embodiment, each ofthe plurality of machines 205A-C in the machine farm 115 are physicallyseparate and distinct computer servers from each other. In alternativeembodiments, at least a portion of the machines 205A-C are distinctcomputing blades within a blade server or blade machine or distinctnodes within a computing grid of nodes. In alternative embodiments, atleast a portion of the machines 205A-C are distinct virtual machinesco-located upon a single physical computing device, but are virtualizedto appear as independent and physically distinct computing devices.

In one embodiment, each of the physically separate and distinct computerservers (e.g., machines 205A-C) and the control hub 195 arecommunicatively interfaced through a high speed network (e.g., 125) ofthe datacenter 110.

In accordance with one embodiment, the lightweight agent 130 isdownloaded and instantiated within memory 201 of each of the pluralityof respective machines 205A-C. In such an embodiment, execution of thelightweight agent 130 is isolated to the memory 201 of each of therespective machines 205A-C. In one embodiment, the one or moreapplications 135 and the one or more dependencies 140 for each of theone or more applications reside only within the memory 201 of therespective plurality of machines. In one embodiment, each of thelightweight agents 130, the one or more applications 135, and the one ormore dependencies 140 for each of the one or more applications 135, donot access or reference hard disk drive storage on any of the pluralityof respective machines 205A-C having the lightweight agent 130downloaded and instantiated thereon. Stated differently, regardless ofwhether any one of the respective machines 205A-C is provisioned with ahard disk drive, the lightweight agent 130 operates memory resident anddoes not rely upon, or make use of, the hard disk drive. In accordancewith other embodiments, the applications 135 and dependencies 140operate in the same manner. In some embodiments, the machines 205A-C areheadless, keyboardless, and diskless, but include at least a CPU andmemory upon which to execute and perform instructions (e.g., “baremetal” machines).

Further depicted within FIG. 2 are elements 250, 255, 260, and 265.Element 250 represents the lightweight agent 130 being provisioned tomachine 205B in accordance with one embodiment. In such an embodiment,the lightweight agent 130 is pushed to machine 205B from control hub195. Element 255 represents the plurality of URLs 170 which are pushedto machine 205B by the control hub 195 enabling machine 205B, via itslightweight agent 130, to pull the appropriate applications 135 anddependencies 140 from the application repository. Element 260 representsthe lightweight agent 130 pulling one or more applications 135 from theapplication repository 190 as specified by the control hub 195 (e.g.,based on the plurality of URLs 170 pushed to the machine). And element265 represents the lightweight agent 130 pulling one or more applicationdependencies 140 from the application repository 190 as specified by thecontrol hub 195 in support of the pulled applications 135.

In accordance with one embodiment, the control hub 195 manages anupgrade procedure for the plurality of machines 205A-C. In such anembodiment, the upgrade procedure includes the control hub issuing agraceful interrupt to each of the plurality of machines 205A-C, in whichthe graceful interrupt permits each respective machine to completecurrently executing work, for example, each of the plurality ofrespective machines 205A-C will allow the one or more applications 135currently executing work to complete (e.g., without early termination)responsive to receiving a graceful interrupt. In one embodiment, theupgrade procedure includes each of the plurality of respective machinesto: stop accepting work instructions responsive to the gracefulinterrupt issued by the control hub; to respond to the control hub witha notification indicating the respective machine is ready to receiveinstructions from the control hub; and to receive upgrade instructionsfrom the control hub 195. In one embodiment, the upgrade procedureoperates asynchronously, such that various operations undertaken by eachof the plurality of respective machines 205A-C will begin and end ontheir own schedules and time tables. For example, one machine may becontinuing execution of its current work, while another machine receivesupgrade instructions from the control hub 195.

In one embodiment, the upgrade procedure further includes the controlhub 195, responsive to receiving the notification from each respectivemachine 205, performs an unloading operation of a test classinstallation (e.g., an application 135) from the machine's memory, viathe machine's lightweight agent (e.g., the control hub 195 instructslightweight agent 130 to unload specified test class or other installedapplication 135). In such an embodiment, the upgrade procedure furtherincludes the control hub 195 to perform an unloading operation of alldependencies 140 associated with the test class installation (e.g.,application dependencies 140) from the machine's memory 201 as specifiedby the control hub 195 (e.g., where the operation is implemented via themachine's lightweight agent). In such an embodiment, the upgradeprocedure further includes the control hub 195 to cause or instruct themachine's lightweight agent to download and install a new application135 from an application repository 190 to the machine's memory 201 asspecified by the control hub 195 and download and install, via themachine's lightweight agent, all dependencies 140 for the newapplication 135 from the application repository 190 to the machine'smemory 201 as specified by the control hub 195. In such an embodiment,the upgrade procedure further includes the control hub 195 to start, viathe machine's lightweight agent, the new application 135 within therespective machine (e.g., one of 205A-C as depicted at FIG. 2, or one of105A-G as depicted by FIG. 1).

In accordance with one embodiment, the lightweight agent 130 implementsa container 203 for managing class objects within each of the respectivemachines 205A-C. In such an embodiment, loading the one or moreapplications 135 into the memory 201 of the respective plurality ofmachines 205A-C includes: a) allocating an exclusive memory space 202for each of the one or more applications 135 within the memory 201 ofthe respective machine (e.g., one of 205A-C); b) uniquely associating adynamically generated URL class loader 231A and 231B for each of the oneor more applications 135 within the exclusive memory space 202 allocatedto the one or more applications 135; and loading, via the uniquelyassociated URL class loader 231A and 231B, each respective application135 into the exclusive memory space 202 and each of the one or moredependencies into the exclusive memory space 202 allocated to therespective application 135 based on the plurality of URL references 170pushed to the lightweight agent 130.

In one embodiment, the container 203 for managing class objectsimplemented via the lightweight agent includes a managed bean server. Inone embodiment, the lightweight agent 130 is implemented as a JVM (JavaVirtual Machine) which includes the managed bean server (e.g.,MBeanServer). In one embodiment, the lightweight agent 130 furtherincludes a Java Remote Method Invocation Application ProgrammingInterface (e.g., a Java RMI), or a Java based or Java compatibleApplication Programming Interface (API) that performs theobject-oriented equivalent of Remote Procedure Calls (RPC), or anotherRemote Method Invocation (RMI) mechanism. The lightweight agent 130 mayfurther include an RMI registry and a custom security manager. In suchembodiments, the lightweight agent 130 acts as a remote agent whencommunicating with the control hub 195. The lightweight agent 130installed onto each of the machines 205A-C in the server farm or machinefarm 115 exposes Transmission Control Protocol (TCP) ports that are usedto send application control requests. The methods for applicationcontrol include, for example, load, stop, start, and unload.Additionally, within the applications 135 themselves, additional methodsmay be arbitrarily defined in accordance with the disclosed embodiments.Such additional methods are available to be executed remotely once theapplication 135 has been loaded into the lightweight agent's 130MBeanServer.

In one embodiment, the MBeanServer is responsible for listening forexternal commands and is additionally responsible for staying alivewithin each of the machines 205A-C (e.g., responsible for keeping itselfand the communication capabilities of the lightweight agent 130 alive sothat each machine remains responsive to remote commands, withoutbecoming a dead node, requiring human interaction, such as a hardreboot). In one embodiment, the managed bean server provides a container203 for plugging in applications 135.

In one embodiment, the managed bean server exposes standard interfacesto the control hub 195. For example, the standard interfaces exposed mayinclude “start” and “interrupt.” In some embodiments, a gracefulinterrupt and a hard interrupt may be exposed, or defined and selectableby the issuing entity (e.g., the control hub 195).

In one embodiment, the managed bean server additionally provides queryand self discovery mechanisms which dynamically discover/identify/findall non-standard and arbitrarily defined interfaces within provisionedapplications 135. In such an embodiment, other than implementingstandard stop, interrupt, stop type methods, custom interfaces definedby code authors are also discoverable and will be exposed by the managedbean server upon discovery, without requiring further intervention. Suchexposed interfaces, whether standard or arbitrarily defined, are thusaccessible to and accessible via the control hub 195 which may issuecommands, instructions, and interactions to the various exposed methodsto launch events, tests, and so forth. Such exposed methods aretherefore also manipulatable via administration consoles and interfacesprovided thorough the control hub 195 as will be described in additionaldetail below.

In one embodiment, at least a portion of the machines 205A-C in themachine farm 115 are provisioned with a JMX (Java™ Management Extension)based or JMX compatible lightweight agent 130 which receives remoteinstructions from a control hub 195. In one embodiment, when anapplication 135 is loaded and an operation is executed remotely, allprocessing happens within a JVM of a JMX based or JMX compatiblelightweight agent 130.

JMX based lightweight agents 130 may automatically pull down application135 code and dependency 140 Java Archives (JARs) from a applicationrepository 190, and subsequently run each application 135 representedwithin the application 135 code and dependency 140 JARs in a separateclassloader but within the same JVM (Java™ Virtual Machine) based or JVMcompatible interpreter. Such a mechanism yields complete control overthe deployment and lifecycle management of deployed Java based or Javacompatible applications in a large scale distributed system, all from asingle remote controller application accessible from, for example,control hub 195. Such an approach may simplify the role of a systemadministrator, and thus reduce cost and complexity and the risk of humanerror on behalf of an Enterprise (e.g., a host organization or abusiness Enterprises and an associated computing environment thatsupports the business objectives of the host organization/businessEnterprise through computing systems in, for example, a datacenter 110or machine farm 115).

In one embodiment, a JMX based or JMX compatible lightweight agent 130loads managed applications 135 and dependent libraries and/orapplication dependencies 140 from an application repository 190 via URLmappings as set forth by one or more of the plurality of URLs 170 pushedto the various machines (205A-C. In such an embodiment, relationshipsbetween the applications 135 and the dependent libraries and/orapplication dependencies 140 are managed within a database schemaaccessible to control hub 195 or via a relationships table structure 290as described above. The database schema and/or relationships tablestructure 290 may reside within control hub 195 as an alternative tobeing accessible from database 155 as described above. In oneembodiment, the applications 135 themselves are packaged as JAR files,and as such, do not include the dependent libraries and/or applicationdependencies 140 because all dependencies 140 are handled withinclassloaders 231A and 231B which are created dynamically within the JMXbased or JMX compatible lightweight agent's 130 MBeanServer. Whendependent libraries and/or application dependencies 140 are needed bythe applications 135, they are populated in the classloader 231A or 231Bassigned to the loaded application 135 operating within an isolatedmemory space (e.g., exclusive memory space 202).

Classloader isolation is supported in accordance with certainembodiments. Classloader isolation facilitates the hosting of multipleapplications 135 within a single JVM, where each application 135 isgiven it's own dynamically generated URL Classloader 231A or 231B. Byisolating each classloader 231A or 231B, dependencies 140 between anapplication 135 and it's corresponding dependent libraries and/orapplication dependencies 140 are strictly maintained while also creatinga process space dedicated to each application within the agent's JVM.For example, exclusive memory space 202 is allocated to the one or moreapplications 135 within the memory 201 of the respective machine (e.g.,one of 205A-C). In certain embodiments, the machine 205A-C and its JMXbased or JMX compatible lightweight agent 130 makes exclusive use of URLClassloaders 231A and 231B, which in turn assures that there are nodependencies 140 on any local file system or hard disk drive within themachine 205A-C upon which the lightweight agent 130.

Embodiments which implement URL class loaders 231A and 231B and managedbean servers as described above additionally make applicationspluggable, and are able to better leverage a highspeed network 125available within the datacenter 110 for downloading and provisioningapplications 135 and dependencies 140 to the machine farm 115.

In accordance with one embodiment, a non-transitory computer readablestorage medium has instructions stored thereon. In such an embodiment,the instructions, when executed by control hub 195 having a processorand memory therein, cause the control hub 195 to perform operations,perform a method, or carry out instructions, for managing a plurality ofmachines 205A-C within a datacenter 110 by implementing operations andfunctionality as described in accordance with the various embodimentsset forth above.

For example, in one embodiment, instructions stored upon anon-transitory computer readable storage medium causes a control hub 195to perform operations including instructing each of a plurality ofmachines 205A-C to download and instantiate a lightweight agent 130(e.g., either JMX based, JMX compatible, or non-JMX based). In such anembodiment, operations further include pushing a plurality of URLreferences 170 from the control hub 195 to the instantiated lightweightagent 130 on each of the plurality of machines 205A-C, in which theplurality of URL references 170 specify one or more applications 135 tobe provisioned and one or more dependencies 140 for each of the one ormore applications 135 also to be provisioned in support of theapplications 135. In such an embodiment, operations further includeinstructing the lightweight agent 130 at each of the plurality ofmachines 205A-C to load the one or more applications 135 and the one ormore dependencies 140 for each of the one or more applications 135 intomemory 201 of the respective one of the plurality of machines 205A-C.

In accordance with one embodiment, a remote control Graphical UserInterface (GUI) is implemented in which each of the plurality ofdeployed lightweight agents 130 are individually graphically displayedvia the GUI and individually controllable via a JMX remote controlclient, implemented as a servlet in the control hub 195. In such anembodiment, connections may be established to each of the plurality ofdeployed lightweight agents 130 by specifying both the JMX and RMI URL'sto create a connection string of the form of:

“service:jmx:rmi://<HOST_NAME>:<JMX_PORT>/jndi/rmi://<HOST_NAME>:<RMI_PORT>/server.”

Upon establishing a connection to one of the lightweight agents 130, twoseparate MBeans are created. A first for the application 135 that isbeing loaded and a second for the classloader 231A or 231B that theloaded application will use (e.g., be uniquely associated with and underthe control of). When the application MBean is created, anapplication-specific classloader MBean is provided to a createMBeanmethod, associating the two MBeans and allowing the application 135 toload its main and dependent libraries and/or application dependencies140 in an isolated manner, within the exclusive memory space 202established for the one or more applications 135 within the memory 201of the respective machine (e.g., one of 205A-C).

A jconsole connection may be established with any of the one or morerunning lightweight agents 130 via the GUI. JConsole is a graphicalmonitoring tool to monitor Java Virtual Machines (JVM) and java based orjava compatible applications on both local and remote machines, such asthe remote applications 135 executing on the machines 205A-C which areremote from the control hub 195.

In one embodiment, the upgrade procedure described above is implementedvia an external client application which uses upgrade informationinserted into the control hub 195 to perform automatic upgrades of JMXbased or JMX compatible applications 135 executing within JMX based orJMX compatible lightweight agents 130. In one embodiment, the externalclient application waits until a targeted application 135 provisioned toone of the plurality of machines 205A-C is marked as offline via thecontrol hub 195. In such an embodiment, the external client applicationthen proceeds to destroy the classloader 231A and 231B and unload theapplication 135 MBean from the JMX based or JMX compatible lightweightagent 130. The lightweight agents 130 disables URLConnection caching toprevent stale classes (e.g., classes embodying applications 135 anddependencies 140) from being used once an upgrade is performed. Inembodiments that make exclusive use of URLClassloaders (e.g.,MLetClassloaders), an upgrade or reload of an application 135 destroysall references to the application 135 and its associated classloader231A and 231B. In such an embodiment, the external client applicationthen reloads the specified application 135 and recreates the classloader231A and 231B MBean to make the application 135 available for executionand management (e.g., makes it deployable 145). MLetClassloaders are aclass that represents the class loader that the m-let service uses toload classes and resources. The term “Mlet” or “M-let” refers to a“Management applet,” which is a utility MBean to load, instantiate andregister MBeans in the MBeanServer.

In one embodiment, a GUI additionally provides an administration consoleto select the machines 205A-C within the machine farm 115, select theapplication(s) 135 executing within the machine farm 115, and/or selectthe associated remote method(s) to invoke which are exposed to thecontrol hub 195 and made accessible and viewable via the GUI of thecontrol hub's 195 administration console, in accordance with the aboveembodiments. For example, such an administration console permits systemadministrators to perform remote operations on applications 135 and toload/unload the applications 135 from deployed lightweight agents 130.The administration console again makes use of the servlet that isexposed on the control hub 195. Such an administration console furtherpermits an administrator to perform operations on multiple lightweightagents 130 deployed within the machine farm 115 concurrently. Forexample, an administrator may start a specific application 135 onseveral different machines 205A-C via the administration console whichpermits the administrator to select the machines 205A-C, select theapplication(s) 135, and select the associated remote method(s) toinvoke, in accordance with the disclosed embodiments.

FIG. 3 shows a diagrammatic representation of a system 300 in whichembodiments may operate, be installed, integrated, or configured.

In one embodiment, system 300 includes a memory 395 and a processor orprocessors 390. For example, memory 395 may store instructions to beexecuted and processor(s) 390 may execute such instructions. System 300includes bus 385 to transfer transactions and data within system 300such as transactions between hardware based control hub 101 and database355 or the data store 350. System 300 further includes database 355which may store a relationship table structure specifying therelationships between available applications and dependencies availablefrom an application repository, and which control hub 301 may provisionto remote machines (e.g., 105A-C as set forth in FIG. 1). Database 355may additionally store a list of remote machines and locationinformation for such machines (e.g., host names, IP addresses, etc.).Alternatively, such a list may be stored within data store 350 (e.g.,list 365).

System 300 includes data store 350 to store data and information. Datastore 350 stores a copy of deployable lightweight agent 330 inaccordance with one embodiment.

Distinct within system 300 is hardware based control hub 301 whichincludes Remote Method Invocation (RMI) Agent 305, Agent Provisioner310, and Machine List Manager 315. In accordance with one embodiment,Remote Method Invocation (RMI) Agent 305 enables hardware based controlhub 301 to remotely communicate with, remotely trigger, remotelyinitiate, and remotely instruct lightweight agents 330 deployed withinmachines in a machine farm to perform actions and events as specified bythe hardware based control hub 301. In such an embodiment, AgentProvisioner 310 deploys the deployable lightweight agent 330 to machineswithin a machine farm and Machine List Manager 315 provides a listing ofthe machines within the machine farm upon which the deployablelightweight agent 330 may be deployed and controlled and a location,location name, IP address, or other appropriate information for themachines in the machine farm so that the deployable lightweight agent330 may be deployed by the hardware based control hub 301.

FIGS. 4A, 4B, and 4C are flow diagrams illustrating methods (400, 401,and 402) for automating deployment of applications in accordance withdisclosed embodiments. Method 400 depicts operations for managing aplurality of machines operating as a machine farm in a datacenter.Method 400 operates within a control hub. Method 401 depicts operationsfor receiving automated deployments and application upgrades. Method 401operates at one of a plurality of machines in a machine farm. Method 402depicts operations for invoking methods within one or more machines in amachine farm from a control hub. Method 402 operates in conjunction withboth a control hub and at least one machine within a machine farm.Methods 400, 401, and 402 may be performed by processing logic that mayinclude hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions run on a processingdevice to perform various operations such as deploying, provisioning,issuing remote commands and control, etc.), or a combination thereof. Inone embodiment, methods 400, 401, and 402 are performed by hardwarelogic, such as the hardware based control hub depicted at element 301 ofFIG. 3 or by a machine within a machine farm such as those depicted atelements 105A-G of FIGS. 1 and 205A-C of FIG. 2. Some of the blocksand/or operations listed below are optional in accordance with certainembodiments. The numbering of the blocks presented is for the sake ofclarity and is not intended to prescribe an order of operations in whichthe various blocks must occur.

Method 400 of FIG. 4A begins with processing logic executing an agentprovisioning script at a control hub (block 405). At block 410,processing logic in a control hub accesses a list specifying a locationname for each of a plurality of machines to be provisioned with alightweight agent.

At block 415, processing logic in a control hub logs into a commandshell on each specified machine from the control hub. The control hubmay continue to execute instructions, or deploy a provisioning scriptwhich, when executed on a target machine, performs operations specifiedby the control hub. At block 420, processing logic instructs, viacommands to a remote command shell, each specified machine to downloadthe lightweight agent from the control hub. Alternatively, the controlhub may deploy and execute the provisioning script, thus causing thetarget machine to pull or download the lightweight agent from thenetwork (e.g., 125).

At block 425, processing logic instructs, via commands to the remotecommand shell, each specified machine to start the lightweight agentpreviously downloaded. Alternatively, the provisioning script mayinstantiate the lightweight agent subsequent to its pull or downloadoperations.

At block 430, processing logic on the control hub pushes a plurality ofURL (Uniform Resource Locator) references from the control hub to theinstantiated lightweight agent on each of the plurality of machinesspecifying applications and dependencies to be provisioned.

At block 435, processing logic on the control hub instructs each of theplurality of machines to load, via the lightweight agent, applicationsand dependencies into a memory of each respective machine.

At block 440, processing logic on the control hubinstantiates/triggers/initiates an upgrade procedure for the pluralityof machines or a portion thereof. At block 445, processing logic on thecontrol hub issues a graceful interrupt to each of the plurality ofmachines in furtherance of the upgrade procedure, or to the portion ofmachines for which the upgrade procedure isinstantiated/triggered/initiated. At block 450, processing logic on thecontrol hub waits for and receives a notification from each of theplurality of machines indicating the respective machine is ready toreceive instructions from the control hub. The notifications from therespective machines are received asynchronously, as each respectivemachine reaches a state at which it issues such notifications.

At block 455, processing logic on the control hub issues upgradeinstructions to each of the plurality of machines (in an asynchronousmanner responsive to each of the received notifications), includingunloading installed applications and dependencies, downloading andinstalling new applications and dependencies, and starting the newapplication(s).

Method 401 of FIG. 4B begins with processing logic executing one of anyof a plurality of machines within a machine farm, where the processinglogic pulls a lightweight agent from a control hub responsive to remoteinstructions from the control hub. Alternatively, the machine receives aprovisioning script from the control hub, executes the provisioningscript, and pulls the lightweight agent from the control hub based oninstructions within the provisioning script (block 460).

At block 462, processing logic in the machine implements a container formanaging class objects.

At block 464, processing logic in the machine receives a plurality ofURL references specifying applications and dependencies to bedownloaded. At block 466, processing logic in the machine downloads theapplications and dependencies via the URL references.

At block 470, processing logic in the machine uniquely associates adynamically generated URL class loader with each application. At block472, processing logic in the machine loads, via the uniquely associatedURL class loader, each respective application and its dependencies intothe exclusive memory space allocated to the applications.

At block 474, processing logic in the machine responds to an upgradeprocedure initiated by the control hub by first receiving a gracefulinterrupt from the control hub. At block 476, processing logic in themachine allows currently executing work of the loaded application(s) tocomplete in view of the graceful interrupt (e.g., the interrupt is not ahard interrupt demanding immediate termination). At block 478,processing logic in the machine stops accepting work instructionsresponsive to the graceful interrupt.

At block 480, processing logic in the machine responds to the controlhub with a notification when the machine is ready to receive furtherinstructions from the control hub (e.g., indicating to the control hubthat it is now ready to proceed with further instructions, otherinstructions, or the upgrade procedure initiated by the control hub).The actual notification sent may be only a “ready” notice or a messageindicating the machine is at a state capable of receiving furtherinstruction.

At block 482, processing logic in the machine receives upgradeinstructions from the control hub, including instructions to unload alltest classes and applications and associated dependencies, to downloadand install a new application and dependencies, and to start the newapplication (e.g., by either instructing the lightweight agent to startthe new application, or by restarting the lightweight agent thus causingit to restart its known applications upon startup).

Method 402 of FIG. 4C begins with processing logic exposing, from amachine in a machine farm, one or more standard methods including atleast start, stop, and interrupt (block 485).

At block 486, processing logic searches, within the machine in themachine farm, one or more applications and dependencies loaded at themachine for arbitrarily defined non-standard methods associated with theone or more applications and dependencies and at block 487, processinglogic exposes, from the machine in the machine farm, the arbitrarilydefined non-standard methods discovered by the search.

At block 488, processing logic at an administration console of a controlhub lists a plurality of machines in the machine farm. For example, theadministration console may list all, active, a zone, a subset, or aspecified type or class of machines, etc.

At block 489, processing logic lists at the administration console, allinvokable methods for each machine listed by the administration console,including both standard methods exposed by each respective machine andarbitrarily defined non-standard methods exposed by each respectivemachine.

At block 490, processing logic at the administration console of thecontrol hub receives a selection specifying one or more standard and/ornon-standard methods to invoke at one or machines listed in the machinefarm.

At block 491, processing logic at the control hub generates one RemoteMethod Invocation (RMI) connection string for every specified standardand/or non-standard method to invoke at each specified machine uponwhich the specified standard and/or non-standard method is to beinvoked. For example, if two machines are selected via theadministration console and two invokable methods are selected at each,four RMI strings would be generated in accordance with such anembodiment.

At block 492, processing logic at the control hub issues the generatedRMI connection strings, for example, invoking them via a networkconnecting the control hub with the machines in the machine farm.

At block 493, processing logic at each machine in the machine farmidentified by at least one RMI connection string receives instructionsto invoke one or more standard and/or non-standard methods and at block494, processing logic at each respective machine identified by at leastone RMI connection string issued from the control hub invokes the one ormore standard and/or non-standard methods in accordance with theinstructions received by the corresponding machine.

FIG. 5 illustrates a diagrammatic representation of a machine 500 in theexemplary form of a computer system, in accordance with one embodiment,within which a set of instructions, for causing the machine 500 toperform any one or more of the methodologies discussed herein, may beexecuted. In alternative embodiments, the machine may be connected(e.g., networked) to other machines in a Local Area Network (LAN), anintranet, an extranet, or the Internet. The machine may operate in thecapacity of a server or a client machine in a client-server networkenvironment, as a peer machine in a peer-to-peer (or distributed)network environment, as a server or series of servers within anon-demand service environment, as a blade within a blade server, as anode within a computing grid, or as a physically separate and distinctmachine within a machine farm of a datacenter. Certain embodiments ofthe machine may be in the form of a personal computer (PC), a tablet PC,a set-top box (STB), a Personal Digital Assistant (PDA), a cellulartelephone, a web appliance, a server, a network router, switch orbridge, computing system, or any machine capable of executing a set ofinstructions (sequential or otherwise) that specify actions to be takenby that machine. Further, while only a single machine is illustrated,the term “machine” shall also be taken to include any collection ofmachines (e.g., computers) that individually or jointly execute a set(or multiple sets) of instructions to perform any one or more of themethodologies discussed herein. Additionally, while the embodiment setforth at FIG. 5 depicts various elements, each of which are describedbelow, not all elements of the machine are required in accordance withcertain embodiments. For example, some embodiments make use of a “baremetal” machine deployed within a machine farm, in which the machineoperates headless (e.g., without a display device such as user interface510) and keyboardless (e.g., without alphanumeric input device 512 andcursor control device 514). In some embodiments, machines within amachine farm operate without use of a hard disk drive. However, in allembodiments, machines deployed within a machine farm include at least aCPU (e.g., processor 502) and memory (e.g., main memory 504), but thecontents of such memory may vary from that which is depicted at FIG. 5.Alternative combinations of elements depicted are utilized in machineswhich embody a control hub, a database, and/or an application server asdescribed in the embodiments set forth above.

The exemplary computer system 500 includes a processor 502, a mainmemory 504 (e.g., read-only memory (ROM), flash memory, dynamic randomaccess memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM(RDRAM), etc., static memory such as flash memory, static random accessmemory (SRAM), volatile but high-data rate RAM, etc.), and a secondarymemory 518 (e.g., a persistent storage device including hard disk drivesand a persistent database and/or a multi-tenant databaseimplementation), which communicate with each other via a bus 530. Mainmemory 504 includes a list of machines (e.g., names and locationinformation for machines in a machine farm) 524 and a deployablelightweight agent 523 which is pushed to communicatively interfacedmachines in a machine farm. Main memory 504 and its sub-elements (e.g.523 and 524) are operable in conjunction with processing logic 526 andprocessor 502 to perform the methodologies discussed herein.

Processor 502 represents one or more general-purpose processing devicessuch as a microprocessor, central processing unit, or the like. Moreparticularly, the processor 502 may be a complex instruction setcomputing (CISC) microprocessor, reduced instruction set computing(RISC) microprocessor, very long instruction word (VLIW) microprocessor,processor implementing other instruction sets, or processorsimplementing a combination of instruction sets. Processor 502 may alsobe one or more special-purpose processing devices such as an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA), a digital signal processor (DSP), network processor, or thelike. Processor 502 is configured to execute the processing logic 526for performing the operations and functionality which is discussedherein.

The computer system 500 may further include a network interface card508. The computer system 500 also may include a user interface 510 (suchas a video display unit, a liquid crystal display (LCD), or a cathoderay tube (CRT)), an alphanumeric input device 512 (e.g., a keyboard), acursor control device 514 (e.g., a mouse), and a signal generationdevice 516 (e.g., an integrated speaker). The computer system 500 mayfurther include peripheral device 536 (e.g., wireless or wiredcommunication devices, memory devices, storage devices, audio processingdevices, video processing devices, etc.). The computer system 500 mayfurther include a Hardware based control hub 534 to manage a pluralityof machines operating as a machine farm within a datacenter inaccordance with the described embodiments.

The secondary memory 518 may include a non-transitory machine-readableor computer readable storage medium 531 on which is stored one or moresets of instructions (e.g., software 522) embodying any one or more ofthe methodologies or functions described herein. The software 522 mayalso reside, completely or at least partially, within the main memory504 and/or within the processor 502 during execution thereof by thecomputer system 500, the main memory 504 and the processor 502 alsoconstituting machine-readable storage media. The software 522 mayfurther be transmitted or received over a network 520 via the networkinterface card 508.

While the subject matter disclosed herein has been described by way ofexample and in terms of the specific embodiments, it is to be understoodthat the claimed embodiments are not limited to the explicitlyenumerated embodiments disclosed. To the contrary, the disclosure isintended to cover various modifications and similar arrangements aswould be apparent to those skilled in the art. Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements. It is tobe understood that the above description is intended to be illustrative,and not restrictive. Many other embodiments will be apparent to those ofskill in the art upon reading and understanding the above description.The scope of the disclosed subject matter is therefore to be determinedin reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The invention claimed is:
 1. A method for managing a plurality ofmachines operating as a machine farm within a datacenter, wherein themethod comprises: executing an agent provisioning script at a controlhub within the datacenter instructing each of the plurality of machinesto download and instantiate a lightweight agent; wherein the agentprovisioning script instructing each of the plurality of machines todownload and instantiate the lightweight agent comprises the agentprovisioning script to: access a list specifying a location name foreach of the plurality of machines to be provisioned with the lightweightagent; and for each of the plurality of machines specified by the list:a) log in to a command shell on the specified machine from the controlhub; b) instruct, by issuing commands to the command shell, thespecified machine to download the lightweight agent from the controlhub; c) instruct, by issuing the commands to the command shell, thespecified machine to start the lightweight agent; pushing a plurality ofURL (Uniform Resource Locator) references from the control hub to theinstantiated lightweight agent on each of the plurality of machinesspecifying one or more applications to be provisioned and one or moredependencies for each of the one or more applications; and loading, viathe lightweight agent at each of the plurality of machines, the one ormore applications and the one or more dependencies for each of the oneor more applications into memory of each respective machine.
 2. Themethod of claim 1: wherein each of the plurality of machines pulls thelightweight agent from the control hub responsive to the agentprovisioning script; and wherein each of the plurality of machines pullsthe one or more applications and the one or more dependencies for eachof the one or more applications from a central application repository.3. The method of claim 2, wherein the control hub and the centralapplication repository each reside on physically separate and distinctcomputer servers, and wherein each of the plurality of machines arephysically separate and distinct computer servers from the control huband the central application repository.
 4. The method of claim 3,wherein each of the physically separate and distinct computer serversand the control hub are communicatively interfaced through a high speednetwork of the datacenter.
 5. The method of claim 1, wherein thelightweight agent is downloaded and instantiated within memory of eachof the plurality of respective machines, and wherein execution of thelightweight agent is isolated to the memory of each of the respectivemachines.
 6. The method of claim 5, wherein the one or more applicationsand the one or more dependencies for each of the one or moreapplications reside only in the memory of the respective plurality ofmachines.
 7. The method of claim 6, wherein each of the lightweightagent, the one or more applications, and the one or more dependenciesfor each of the one or more applications do not access or reference harddisk drive storage on any of the plurality of respective machines havingthe lightweight agent downloaded and instantiated thereon.
 8. The methodof claim 1: wherein the lightweight agent implements a container formanaging class objects; and wherein loading the one or more applicationsinto the memory of the respective plurality of machines comprises: a)allocating an exclusive memory space for each of the one or moreapplications within the memory of the respective machine; b) uniquelyassociating a dynamically generated URL class loader for each of the oneor more applications within the exclusive memory space allocated to eachof the one or more applications; and loading, via the uniquelyassociated URL class loader, each respective application into itsexclusive memory space and each of the one or more dependencies into theexclusive memory space for the respective application based on theplurality of URL references pushed to the lightweight agent.
 9. Themethod of claim 8, wherein the container for managing class objectsimplemented via the lightweight agent comprises a managed bean server.10. The method of claim 1, wherein the control hub manages a databasespecifying relationships between all available applications and alldependencies for the available applications.
 11. The method of claim 1,wherein the control hub manages an upgrade procedure for the pluralityof machines, the upgrade procedure comprising: the control hub issuing agraceful interrupt to each of the plurality of machines, wherein thegraceful interrupt permits each respective machine to complete currentlyexecuting work; wherein each of the plurality of respective machines to:a) allow the one or more applications currently executing work tocomplete; b) stop accepting work instructions responsive to the gracefulinterrupt issued by the control hub; c) respond to the control hub witha notification indicating the respective machine is ready to receiveinstructions from the control hub; and d) receive upgrade instructionsfrom the control hub.
 12. The method of claim 11, wherein the upgradeprocedure further comprises the control hub, responsive to receiving thenotification from each respective machine, to perform operationsincluding: unloading, via the machine's lightweight agent, a test classinstallation from the machine's memory; unloading, via the machine'slightweight agent, all dependencies associated with the test classinstallation from the machine's memory as specified by the control hub;download and install, via the machine's lightweight agent, a newapplication from an application repository to the machine's memory asspecified by the control hub; download and install, via the machine'slightweight agent, all dependencies for the new application from theapplication repository to the machine's memory as specified by thecontrol hub; and start, via the machine's lightweight agent, the newapplication within the respective machine.
 13. A non-transitory computerreadable storage medium having instructions stored thereon that, whenexecuted by control hub having a processor and memory therein, theinstructions cause the control hub to perform operations for managing aplurality of machines within a datacenter, wherein the operations to beperformed comprise: instructing each of the plurality of machines todownload and instantiate a lightweight agent; wherein instructing eachof the plurality of machines to download and instantiate the lightweightagent comprises an agent provisioning script on the control hub to:access a list specifying a location name for each of the plurality ofmachines to be provisioned with the lightweight agent; and for each ofthe plurality of machines specified by the list: a) log in to a commandshell on the specified machine from the control hub; b) instruct, byissuing commands to the command shell, the specified machine to downloadthe lightweight agent from the control hub; c) instruct, by issuing thecommands to the command shell, the specified machine to start thelightweight agent; pushing a plurality of URL (Uniform Resource Locator)references from the control hub to the instantiated lightweight agent oneach of the plurality of machines, the plurality of URL referencesspecifying one or more applications to be provisioned and one or moredependencies for each of the one or more applications; and instructingthe lightweight agent at each of the plurality of machines to load theone or more applications and the one or more dependencies for each ofthe one or more applications into memory of the respective plurality ofmachines.
 14. The non-transitory computer readable storage medium ofclaim 13, wherein each of the plurality of machines pulls thelightweight agent from the control hub responsive to the agentprovisioning script; and wherein each of the plurality of machines pullsthe one or more applications and the one or more dependencies for eachof the one or more applications from a central application repository.15. The non-transitory computer readable storage medium of claim 13,wherein operations to be performed further comprises the control hub toperform an upgrade procedure for the plurality of machines, wherein theupgrade procedure comprises operations including: issuing, via thecontrol hub, a graceful interrupt to each of the plurality of machines,wherein the graceful interrupt permits each respective machine tocomplete currently executing work; wherein each of the plurality ofrespective machines to: a) allow the one or more applications currentlyexecuting work to complete; b) stop accepting work instructionsresponsive to the graceful interrupt issued by the control hub; c)respond to the control hub with a notification indicating the respectivemachine is ready to receive instructions from the control hub; and d)receive upgrade instructions from the control hub to download, install,and start a new application as specified by the control hub.
 16. A datacenter comprising: a control hub having a memory and processor thereinto execute instructions; an application repository having a memory andprocessor therein to execute instructions, a data store, one or moreapplications stored upon the data store, and one or more dependenciesfor the one or more applications stored upon the data store; and aplurality of machines, each having a memory and processor therein toexecute instructions; wherein an agent provisioning script within thecontrol hub to instruct each of the plurality of machines to downloadand instantiate a lightweight agent, wherein the agent provisioningscript on the control hub to instruct each of the plurality of machinesto download and instantiate the lightweight agent comprises the agentprovisioning script to: access a list specifying a location name foreach of the plurality of machines to be provisioned with the lightweightagent; and for each of the plurality of machines specified by the list:a) log in to a command shell on the specified machine from the controlhub; b) instruct, by issuing commands to the command shell, thespecified machine to download the lightweight agent from the controlhub; c) instruct, by issuing the commands to the command shell, thespecified machine to start the lightweight agent; wherein the agentprovisioning script to push a plurality of URL (Uniform ResourceLocator) references from the control hub to the lightweight agent oneach of the plurality of machines specifying an application and one ormore dependencies, and wherein the agent provisioning script to instructthe lightweight agent at each of the plurality of machines to load theone or more applications and the one or more dependencies from theplurality of URLs into memory.
 17. The data center of claim 16: whereineach of the plurality of machines to pull the lightweight agent from thecontrol hub responsive to the agent provisioning script; and whereineach of the plurality of machines to pull the one or more applicationsand the one or more dependencies for each of the one or moreapplications from a central application repository.